Application Cases

Name of experiment：experimental study of bone surface temperature rise by high voltage amplifier under alternating electric field

Research direction：alternating electric field

Purpose of experiment：the microstructure of bone is very complex, and the electro-mechanical properties of bone have not been fully understood up to now, which is the main reason for the relatively slow progress in the research of using electrical signals to influence bone growth. To solve this problem, the electro-mechanical properties of bone can only be studied from various aspects until they are fully understood. Therefore, this paper aims to explore the changes of bone temperature under the action of alternating electric field.

Test equipment：fresh bovine tibial shaft, waveform generator, ATA-2081 high voltage amplifier, digital video microscope, infrared thermometer.

Experimental process：

In this experiment, a total of 5 dry bone samples were taken from the same bovine tibia along the thickness direction parallel to two samples (samples No. 4 and No. 5), and the other 3 samples were taken from different bovine tibia (sampling locations along the thickness direction were random).

During the experiment, the bottom end of the bone sample was fixed on the fixture, and the top was free to form a cantilever beam. An alternating electric field is applied to the sample through an electrode. The waveform generator outputs sinusoidal alternating voltage with adjustable frequency, and the high voltage amplifier amplifies the amplitude of the output voltage to the set value. The lens of a digital video microscope focuses on a region on the surface of the specimen. Digital image correlation method (DIC) was used to measure the flexural deflection of free end section. The infrared thermometer was used to measure the surface temperature changes of bone samples during the loading time. The resolution of temperature measurement was 0.1℃, and the error range was 0.5℃. The whole experimental device is placed on the optical shockproof platform.

experimental facilities

Result of experiment：

（1）Temperature changes of bone samples at different frequencies and voltage of 70V

（1）By comparing the temperature change and deformation of the classical dielectric, it can be seen that the temperature rise of the classical dielectric is very low under the action of the alternating electric field. Within the measurement error of the thermometer, although the applied electric field can cause both the temperature rise of bone and the bending deformation, the relative high temperature rise caused by it is its unique property. Compared with the bone samples under the DC electric field, it can be seen that under the same voltage value, the temperature rise and deformation of bone under the DC electric field are significantly smaller than that of the AC electric field. Therefore, the temperature rise of bone materials mainly reflects the AC property rather than the simple resistive heating, and the temperature rise of bone originates from the organic component collagen fiber. According to the fitting experimental data, the surface temperature rise of the bone sample under the alternating electric field is proportional to the square of the loading voltage, which is the classical property of the dielectric.